Such an airbag has already been disclosed in the generic German patent application DE 102 36 859 A1 in which the wall section that can be turned inside or outside is a tube-like wall section that has a gas outlet opening. A first end of the control strap is fastened to the tube-like wall section near the gas outlet opening and a second, opposite end of the control strap is attached to the airbag wall. The length of the control strap and the attachment point of the second end of the control strap are selected such that the control strap is tensioned while the airbag unfolds largely unhindered, and the tube-like wall section along with the gas outlet opening is pulled into the interior of the airbag. As a result of the pressure prevailing inside the airbag, the tube-like wall section is compressed such that the gas outlet opening is closed. Consequently, in the case of an optimal restraint position of the vehicle occupant and thus under good airbag unfolding conditions, undesired gas loss is minimized. In contrast, if the vehicle occupant is situated in an unfavorable restraint position, for example too close to the airbag, the unfolding of the airbag is hindered. In this case, the control strap does not become tensioned, so that the tube-like wall section is turned outside and the gas outlet opening is released. In this manner, an excessive airbag hardness is prevented when the vehicle occupant is in an unfavorable restraint position.
A drawback of the described airbag is that the opening cross section of the gas outlet opening cannot be varied or adapted. The opening is either essentially completely closed or completely open. However, an adaptation of the outflow cross section that can be regulated, preferably passively regulated, would be desirable in order to improve the restraint values of the airbag.
Therefore, it is an object of the invention to create an airbag with a gas outlet opening, the gas outlet opening providing an outflow cross section being controllable, preferably reversibly and path-dependently controllable, by a passive regulation device.